I'm about ninety percent certain that Rothco does not make their own cord.
750 lbs. sounds rather absurd. I don't think that is their paracord that states that. They sell other types of cord and rope too.
Their nylon Paracord is labeled "Rothco Nylon Paracord Type III 550lb" "Made in the U.S.A."
It does say Made in the U.S.A. And if that's the case then it should be of decent quality. I believe all U.S. manufacturers of Commercial Paracord are also suppliers of Mil-Spec cord to the U.S. Military. The U.S. cord is made of nylon.
They also sell a polyester Commercial Paracord. It is plainly marked that it is polyester and made in China.
Read my articles about Commercial Paracord and Mil-Spec cord @
knotsandknotting.blogspot.com/